Renewal is sought for a program project grant in statistical and quantitative genetics in North Carolina State University. The objectives of the proposal are to conduct research in statistical and quantitative genetics, with an ultimate goal of developing a methodology for understanding the genetic basis and evolution of complex characters. The program consists of an administrative core and eight individual projects. The core provides administrative, computing and statistical services to the other projects and maintains communication among all projects. Project 1 is concerned with population structure, the location of human disease genes and individual identification. Project 2 develops methods for locating genes affecting quantitative traits for data collected from crosses between inbred lines, for sets of sib-pairs, and for individuals samples randomly from outbred populations. Project 3 constructs probabilistic models to investigate the variation of evolutionary rates over time, and to relate protein structure to protein evolution. Project 4 adopts a molecular approach for the study of structure and function of biomolecular sequences, allowing for the correlations that arise from the common evolutionary origins of homologous sequences. Project 3 adds a developmental component to the study of the origin, development and evolution of complex traits. Quantitative trait loci will be sought for development rate in mice, and conditional epistatic variance models will be used to predict times of gene activity. The effects of uterine maternal effects on lifespan in mice will be investigated. Project 6 seeks an understanding of the genetic basis of quantitative variation in longevity in Drosophila melanogaster. Candidate genes and gene regions will be sought that alter adult lifespan, and quantitative trait nucleotides responsible for naturally occurring variation in lifespan will be mapped. Project 7 will establish Drosophila as a model organism for quantitative genetic dissection of complex neurotransmitter-modulated traits, including prepupal heart rate and five reflex behaviors. Marker-trait associations will be studied for heart rate, and the mutational distribution of P-element insertions on tyrosine-associations will be studied for heart rate, and the mutational distribution of P-element insertions on tyrosine- and dopa-decarboxylase activity will be characterized. Project 8 will relate nucleotide sequence diversity and genome evolution in the loblolly pine. Diversity will be estimated and gene family structure will be established.